Manufacture of 2.3-hydroxynaphthoic acid



Patented Aug. 5, 1924.

UNITED. STATES v 1,503,9 PATENT OFFICE. f

LEE H. CONE, Oi! MOUNTAIN LAKES, NEW JERSEY, ASSIGNOR TO NATIONAL AN I & CHEMICAL COMPANY, INC., 01 NEW YORK, N. A. CORPORATION OF NEW YO.

MANUFACTURE OF 2.3-HYDROXYNAPHTHOIO ACID.

No Drawing.

of New Jersey, have invented certain new and useful Improvements in the Manufacture of 2.3-Hydroxynaphthoic Acid; and I I do hereby declare the following to be a full,

clear, and exact description of the invene tion, such as will enable others skilled in the art to which it appertains to make and use the same. v v

This invention relates tQimproVements 1n the manufacture of sodium beta-naphtholate and in the manufacture of 2.3-hydroxynaph thoic aci'd therefrom. In the manufacture of 2.3-hydroxynaphthoic acid from sodium naphtholate it 1s essential that the sodium naphtholate be dry and in a condition to absorb carbon dioxide. Sodium naphtholate can readily be prepared on a laboratory scale in the form of a fine dry powder byevaporation of the aqueous solutions of the naphtholate under reduced pressure and with agitation; but this method of preparation presents considerable difficulty when carried out on a plant scale, ow-

.ing to the tendencyof the material to form into lum s or balls from which the water is driven o with difliculty, while the resulting naphtholate, when subjected to a conversion temperature-in the presence of carbon d1- oxide, tends to overheat in spots with consequent decomposition of the acid produced therefrom.

According to the present invention these difiiculties are overcome or minimized, and the sodium beta naphtholate is produced in a finely divided dry state and in a form well adapted for use in the manufacture of 2.3- hydroxynaphtho ic acid therefrom.

The present invention is based upon the discovery that the water can readily be driven off from a solution of sodium betanaphtholate and the naphtholate obtained divided condition by in a dry and finel heating a solution 0 thenaphtholateln contact wlth an indifferent solvent or diluent,

such as melted paraflin, the dry sodium naphtholate being thus obtained in a finely divided condition in admixture with the molten parafiin. The inventlon is based upon the further discovery that the finely divided naphtholate so produced, and still in admixture with and suspension the molten paraf- Application filed February 15, 1922. Serial No. 5863M. I

fin can be readily converted into 2.3-hydroxynaphthoic acid by the action of carbon dioxide under pressure and at an elevated temperature. The invention, accordinglyfineludes improvements both in the manufacture of the sodium beta-naphtholate, and in the manufacture of the 2.3-hydroxynaphthoic acid therefrom.

The indifferent solvent or diluent utilized in the process should be. one which is not substantially volatile at the temperatures employed, and particularly at the temperatures emplo ed in the treatment of the dry naphtholate With'carbon dioxide. That is, the inert diluent should not distill at a'temperature below about 250 C. Ordinary parafin wax, for example, that known to the trade as crude white scale and melting at 124126 F. is well adapted for use. The melting point, preferably below that of the boiling point of Water, does not appear to be of importance, and the material may be liquid at ordinary temperatures, as in the case of high boiling paraflin oils, boiling above 250 C. The present invention, accordingly, includes the drying of the sodium beta-naphtholate and its subsequent carbonation and conversion-in the presence of a liquid medium having a boiling point above the conversion temperature and which will not combine or react with the sodium beta-naphtholate or with the hydroxynaphthoic acid formed therefrom. I

The invention will be further illustrated by the following specific examples, but it of parafiin wax, for example, equal in wei ht to that of the beta-na hthol, although t 's amount may be varie somewhat with the type and size of the autoclave. The mixture is heated in the autoclave under reduced pressure and, whenthe water is nearly all driven off, the tem erature is gradually raised to about 200 a sufiicient time to complete the dehydration. This results in the production of a finely divided dry naphtholate suspended in the molten arafiin, while by cooling with a itation, a so id mass of parafin is obtained w1th the naphtholate unifor ly di tributed and held there for v throu h it. The naphtholate is thus protected by the parafiin and can be reserved in this way for shipment or until 1t is to be used.

When the dry naphtholate is to be used directly for the production of the 2.3- hydroxynaphthoic acid it is not necessary to separate the naphtholate from the paratfin, but the resulting mixture can be directly used. In practice the. hot mlxture of melted parafiin and naphtholate 1s allowed to cool, for example, only to about 125 to 130 C., and is then subjected to agltatlon and to the action of carbon dioxide under pressure, and, finall to a temperature around 250 C. While the carbonation of the naphtholate does, not proceed as rapidly as with a finely divided dry naphtholate without the presence of a material such as parafiin, it nevertheless proceeds with fair rapidity. The carbonation and conversion are completed by raisin the temperature to about 250 C. The by roxynaphthoic acid is thus produced in admixture with the paraflin.

In order to separate the hydroxynaphthoic acid from the paraffin, the mass may be allowed to cool only to a sufiicient temperature to remove it from the autoclave, and thentreated with hot water which dissolves the sodium salt of the hydroxynaphthoic acid while the paraflin floats on top of the solution. The paraflin can be removed by running it ofi while hot, or the solution and paraffin may be allowed to cool and theparaflin removed in a .solid state. The parafiin so removed and recovered can be used over again with only .such loss as 1s incident to handling it during the process.

It will thus \be seen that the drying of the naphtholate and the conversion of naphtholate into the hydroxynaphthoic acid are effected in the presence of the indiflerent solvent or diluent, such as paraflin, and that the conversion of the naphtholate by treatment with carbon dioxide, contrary to what might be expected, readily takes place even though the naphtholate is suspended in and protected by the indifferent diluent. The process is well adapted for use for the roduction of .the hydroxynaphthoic aci as well as for the production of the sodium beta-naphtholate, where that product is desired as the product of the process.

The invention is applicable to the production of alkali salts of phenols other than sodium beta-naphtholate, as well as to the manufacture df carboxylic acids therefrom.

I claim:

1. The method of making dry sodium beta-naphtholate which comprises heating a solution of the na htholate 1n the presence of an indifferent dilhent.

2. The method of making dry sodium beta-naphtholate which comprises heating a solution of the naphtholate 1n the presence of paraflin in a liquid state.

3. The method of making 2.3-h droxyvolatile at the temperature of reaction, to a the action of carbon dioxide under pressure and at a temperature of about 200 to 250 C.

4. The method of making 2.3-hydroxynaphthoic acid which comprises subjecting dry sodium naphtholate, in the presence of molten paraflin substantially non-volatile at the temperature of reaction, to the action of carbon dioxide under pressure and at a temperature of about 200 to 250 C.

5. The method of producing 2.3-hydroxynaphthoic acid which comprises heating a solution of sodium beta-naphtholate in the presence of an indifferent dlluent to remove the water and give a finely divided dry naphtholate in suspension in such diluent, and subjecting the dry sodium naphtholate while still in admixture with such diluent naphthoic acid which comprises heating a solution of sodium beta-naphtholate in the presence of molten paraffin to remove the water and give a finely divided dry naphtholate in suspension in such material, and subjecting the dry sodium naphtholate while still in admixture with such material to the action of carbon dioxide under pressure and at an elevated temperature.

7. The process of producing 2.3-hydroxynaphthoic acid which comprises dryin sodium beta-naphtholate in admixture wit an indifferent non-aqueous liquid vehicle and efl'ecting the carbonation and conversion of the naphtholate in the presence of such vehicle.

I 8. The method of producing-2.3-hydroxynaphthoic acid which comprises drying sodium beta-naphtholate in admixture with a liquid vehicle which will not give an appreciable vapor pressure at the temperatures employed and will not react with the naphtholate nor with the hydroxynaphthoic acid, and effecting the carbonation and conversion of the naphtholate in the presence of such vehicle.

9. The method of producing 2.3-hydroxynaphthoic acid which comprises forming a mixture of melted paraflin and a water solution 'of' sodium beta-naphtholate and heating the solution under reduced pressure tholate and finally dissolvin out the prodent substantially non-volatile at the temder reduced pressure at a temperature of 'vated tem perature of reaction, tothe action of carbon dioxide under pressure and at an elerature.

12. Sodium beta-naphtholate in the form of a finely divided dry powder in admixture in suspension in a solidified indifferent ve-' hicle:

13. The method of making dry sodium beta-naphtholate'in admixture with parafiin, which comprises evaporating to drynem under reduced pressure a solution of the naphtholate in the presence of melted parafiin;

14. The method of making dry and finely divided sodium beta-naphtholate commixed with a solid indifl'erent vehicle, which comprises evaporating to dryness an aqueous solution of sodium beta-naphtholate ,in the presence of an indifferent and melted diluent which is solid at ordina ture, and subsequently cooling t while it is 'being agitated.

15. The method of makin finely divided and dry sodium beta-napht olate admixed with and distributed through solid paraflin, which comprises evaporating to dryness un- 0 mixture 11 from the sotemperaabout 200 C. an aqueous solution of sodium beta-naphtholate in the presence of parafiin having a melting point of 124- 126 F., and subsequently cooling the mixture while. it is being agitated.

16.- In the process of making dr sodium beta-naphtholate b heating a'so ution of sodium beta-napht olate, the improvement which comprises car ing out the operation in the presence of an mdifierent organic dil uent.

17. In the naphthoic acid by the action of carbon oxide on sodium beta-naphtholate, the step of causing the action to occur in the presence of an indifferent organic diluent.

1-8. The method of making dry sodium 'beta-naphtholate, which comprises heating a mixture of sodium h droxide' and betanaphthol in substantial y ual molecular proportions in the presence 0 an indifierent diluent.

19. The method of maln'ng dry. alkali metal phenolates, which comprises heating a mixture of caustic alkali and the phenol in substantially ual'molecular proportions in the presence 0 an indifl'erent diluent.

20. The method of making dry alkali metal phenolates, which comprises heating a solution of the phenolates in the presence of an indifferent diluent.

21. The method of making dry alkali metal phenolates, which comprises heating a solution of the phenolates in the presence of parafiin in a liquid state.

ture.

LEE H. CONE.

In testimony whereof I afiix my signaprocess of making 2.3-hydrox 1-1 

